The trocar is a sharp-pointed instrument incased in a cannula or sheath, which leaves the sharp point of the trocar free.
The rim surrounding the mouth of the cannula should be in contact with the skin.
Attached to the handle was a thumb-rest and a tube for removing or adding fluids and a perforator within the cannula.
The operation is performed with a combined instrument called the trocar and cannula.
It is occasionally necessary to keep the cannula in the stomach for several hours.
Wind colic may need prompt use of the trocar and cannula to puncture high up in the right flank for liberation of gas.
He inserted a cannula of silver through the mouth until its head met an obstruction.
It is well, accordingly, to observe the cannula closely, and if gas is found to be issuing from it it should not be removed.
Intubation, or the passage of a cannula through a stricture, is referred to later.
The instruments used are a small trocar and cannula, which are introduced between the eighth and ninth ribs.
cannula can·nu·la or can·u·la (kān'yə-lə)
n. pl. can·nu·las or can·nu·lae (-lē')
A flexible tube, usually containing a trocar at one end, that is inserted into a bodily cavity, duct, or vessel to drain fluid or administer a substance such as a medication.